Hitherto, as this type of seat slide device for a vehicle, a seat slide device for a vehicle as disclosed in, for example, Patent Literature 1 [PTL 1] is known. The seat slide device for a vehicle includes a lower rail, which is to be fixed to a vehicle floor, an upper rail, which is to be fixed to a seat and supported so as to be freely movable relative to the lower rail, and rolling elements such as rollers or balls, which are each made of steel and arranged in a portion between the lower rail and the upper rail. The lower rail and the upper rail are each formed by bending a metal plate into a predetermined shape through roll forming or press working, and the rolling elements are arranged only in two regions on each of those lower rail and upper rail, which are respectively closer to a front end and a rear end thereof in a longitudinal direction. Further, in order to maintain a constant interval between the rolling elements arranged in the two regions at the front and rear of each rail, rolling element cages extending in the longitudinal direction of the rail are each arranged in a gap between the lower rail and the upper rail. The rolling element cage is also formed by bending the metal plate.